Automatic furnace



,July 22, 1941. N. M; LOWE-R AUTOMATIC FURNACE Filed May 17, 1938 4 Sheets-Sheet 1 .Matha/7M. Lower.

fa-t/ ATTORNEY July 22, 1941. N. M. LOWER AUTOMATIC FURNACE Filed Main; ;L9s8 4 sheets-sheet 2 4 Sheets-Sheet 3 IN VENT OR. an M. Lou/ er fjacn/ TTORNEYJ N. M. LOWER AUTOMATIC 'FURNACE Filed May 17, 1938 WY" Nafh July 2z, 1

TLCI

EIL /06 N. M. LowER 2,250,114-

AUTOMATIC FURNACE Filed Mayv 17, 1938 4 Sheets-Sheet 4 im v [Z4-Figli.

INVENTOR. Lower' ATTORNEY Nalhan M.

Patented July 22, 1941 NT @FFICE l Claims.

This invention relates to automatic stolring mechanism.

One object of the invention is to provide a simple and eflicient stoking mechanism capable of feeding fuel to a plurality of furnaces.

Another object of the invention is to provide a simple and efficient mechanism for delivering fuel to a plurality of furnaces and for removing the ashes from a plurality of furnaces and operat ing said fuel feeding means and said ash removing means in timed relation.

A further object of the invention is to provide in a stolzer feeding fuel to a plurality of furnaces, novel and simple means for independently varying the quantity of fuel delivered to each of the furnaces.

A still further object of the invention is to provide simple and eiiicient mechanism for removing ash from a plurality of furnaces that takes up a minimum of space above the furnace room floor.

` With the above and other objects and advantages in view, the invention consists in the features of construction, the combination of elements and arrangement of parts hereinafter more fully described and claimed, and illustrated in the accompanying drawings, in which Fig. l is a front elevation of a furnace installation showing the novel fuel feeding and ash removing mechanism applied thereto, parts being broken away and shown in section;

Fig. 2 is a side elevation of the furnace installation showing the novel fuel feeding and ash removing mechanism applied thereto, parts being broken away and shown in section;

Fig. 3 is a horizontal sectional view through the furnace installation partially through the ash pit to show the ash conveying mechanism and partially at a higher elevation to show the fuel feeding mechanism;

' Fig. 4 is a fragmentary sectional view on the line 4`4 of Fig. 1;

Fig. 5 is a fragmentary sectional view on the line 5 5 of Fig. 4, parts being broken away;

Fig. 6 is a fragmentary front elevation of a furnace installation showing the mechanism for operating a modified4 form of fuel distributing apparatus;

Fig'. 7 is a fragmentary sectional view on the line 1--1 of Fig. 6, showing the modified form of f-uel distributing mechanism;

Fig. 8- is a fragmentary sectional view on the line 8-8 of Fig. 'l with the flredoor removed; and

f spective side openings. Veys fuel through the conduit 26.

Htl-105.5)

each being provided with a pair of retorts I I having grates I2. The upright walls I3 of the furnaces are in a common plane and each is provided with a pair of openings I4, above the level of the grates I2, providing access to the retorts II.- Firedoors I5 hinged at I6 form closures for each of the respective openings I4. The furnaces are provided with longitudinally extending trough-like ash pits Il, one beneath each of the retorts II, formed by the sloping walls I8, eX- tending preferably beneath the level of the furnace. Clean-out doors 20 are provided permitting access to the ash pits I'I.

A stoker is provided for mechanically delivering fuel from a source of supply (not shown) to the retorts II. The stoker includes a horizontal conduit 2 I, preferably disposed below the level of the furnace room floor I9, leading from the source of fuel supply to one side of the furnace. At its end adjacent the furnace, the conduit 2I communicates with the lower end of a riser conduit 22 that extends upwardly along the furnace side wall 23 to a position immediately forward of the plane of the furnace wall I3 and immediately below the level of the openings I4. A screw conveyor 24 conveysy fuel through the conduit 2I and a screw conveyor 25 elevates the fuel through the riser conduit 22,. Spaced from and extending horizontally along the furnace walls I3 subjacent the openings I4 therein is a conduit 26. The adjacent ends of the conduits 22 and 26 are provided in their respective side walls with openings and a connecting conduit 2-1 lprovides communication between the conduits 22 and 26 through their re- A screw conveyor 28 con- The conduit 26 is provided with laterally projecting chambers 29, one subjacent each of the openings I4, into which chambers fuel is delivered by the screw conveyor 28. The chambers 219 open upwardly at about the level of the bottom of the openings I4 and the bulged portion 30 of each of the doors I5 forms a hood over a respective chamber 29'.` A short vertical screwl conveyor 3| is mounted in each of the chambers 29 elevating fuel therethrough and forcing it through the hood portion 30 above the chambers and into the furnace openings I4. If at times fuel accumulates at the end of the conduit 26 by reason of failure of one or more of the vertical screw conveyors 3| or for some other reason, the plunger |55 is forced to the left against the pressure of the spring I5I, moving the lever |52 which is connected to a circuit breaker E53 for stopping the motor that drives the stoker. A trap door |54 is provided, so that the accumulated coal may be removed and the plunger will be permitted to resume its original position.

At their upper edges each of the chambers 29 is provided with a horizontal plate-like distributor table 32 extending into a respective opening i4 closely adjacent the lower margin thereof, arranged to receive fuel from the chambers 29. The distributing tables 32 are each provided at their respective rearward central portions with a raised portion 33 extending above the fuel receiving surface of the table, in which there is formed a chamber 3 arranged to receive fluid under pressure from a suitable sour-ce of supply. The front face 35 of the raised portion 33 is preferably arcuate in shape and is provided with laterally spaced jet openings 36 communicating with the pressure uid chamber 34 and directed a-cross the surface of the table 32. Curved upstanding ribs 31 are provided at the forward endof the table 32, arranged to deiiect a portion of the projected fuel to the rear corners of the retorts.

With the above construction and arrangement of'parts fuel may be mechanically delivered to the retorts with practically no obstruction in the firing opening. The lredoors can be opened `and access to the rebox had for purposes of inspection or repairs without disturbing or dismantling any part of the stoking mechanism. Immediately in front of the furnaces a depression is formed in the furnace-room floor forming a compartment 38. VThe portion of the troughlikeash pits i1 beneath the level `of the furnaceroomiioor open into the compartment 38. Y Short horizontal longitudinally extending conduits 39 form continuations ofthe ash pits l1 and extend into the compartment 38. A screw conveyor 45 is mounted in each of the ash pits I1 and extends into the conduit 39, conveying the ash from the pits l1. The conduits 35 are provided with downwardly opening discharge outlets 4I opening into a horizontal trough 42 disposed in the compartment 38. A screw conveyor l43 in the trough 42 conveys the ash to the Vbase of the riser conduit 44. The riser conduit 44 extends upwardly above the level of the floor at one side of the furnace i3 and a screw conveyor 45 elevates the ash through the riser conduit 44. At its upper end the riser conduit 44 is provided withv a downwardly opening spout 45 through which the ash drops into an ash receptacle 41.

The ash conveyor and the Stoker fuel conveyor are operated from the same source of power, la motor 48, and their operation is thus lin timed relation. The motor 43 is mounted in a compartment 49 disposed at one side of the furnace beneath the level of the furnace room floor. Mounted in the compartment 49 is .a longitudinally extending shaft i) connected at one end with the motor 48 through a speed reducer 5l. On the shaft 50 is keyed a worm 52 meshing with a worm gear 53 mounted on the shaft extension v54 ofthe screw conveyor 24 for operating the latter. Y

On the same shaft 50 is keyed a second worm 55 which meshes with a worm gear 55 mounted on the lower shaft extension 51 of the fuel elevating screw 25, operatively connecting the elevating screw 25 with the shaft 50. The adjacent ends of the elevating screw 25 and horizontal screw 23 are provided with the shaft extensions 58 and 59, respectively, projecting exteriorly of the conduits housing the screw conveyors. A worm gear @Il on the shaft extension 58 engages a worm 6| on the shaft extension 59 for operating the screw conveyor 28.

On the shaft extension 59 there is also mount- Ved a gear 52 meshing with a gear 63 mounted on a horizontal shaft 64 extending transversely of the furnace front wall beneath the conduit 26 operatively connecting the shaft 54 with the horizontal screw 28. On the shaft 54 and ladjacent each of the chambers 29 are mounted the worms 65 engaging the worm gears 8S in housings 61 at the base of the chambers 29 for operating the vertical screw sections 3 i.

In the compartment 49, offset laterally and below the level of the shaft 55, there is mounted a shaft 15, its rearward end being beneath the Vlevel of the forward end of the shaft 50. On the adjacent offset ends of the shafts 5i) and 15 are mounted the sprocket wheels 16 and 11, respectively, over which passes a sprocket chain 15, for driving the shaft 15 from the shaft 50. On the opposite end of the shaft 15 is mounted a worm 19 meshing with a worm gear 80 mounted on the shaft extension 8i of the ash conveying screw i3 for operating the latter, Mounted on a shaft extension 52 of the opposite end of the ash conveyingscrew 43 is a sprocket wheel 83. A shaft 3d is mounted in the compartment 38 above the level of the trough |22 and at the same level as the ash conveying screws 40 and has mounted thereon at one end a sprocket wheel 85. A sprocket chain passes over the sprocket wheels $3 and t5 operatively connecting the shaft Sil with the ash conveying screw 43.

Mounted on the shaft B4 are a plurality of bevel gears 81 meshing with bevel gears 88 on the extensions S9 of the ash conveying screws 40 for operating the latter. On the shaft 15 between the worm 19 and the sprocket wheel 11 is mounted a worm engaging a worm gear 9| mounted on the lower shaft extension 92 of the ash elevating screw 45, operatively connecting the screw 44 with shaft 15.

The amount of fuel delivered to the retorts Il may be varied by raising and lowering the vertical screw sections 3 l and means, best shown in Fig. 4, is provided for raising and lowering the screw sections 3! independently of each other whereby the amount of fuel delivered to the retorts may be independently varied. It is well known that a screw conveyor working in a horizontal conduit will have a greater conveying action along one side of its axis than the other. Referring to Fig. 5, the screw conveyor 28, when viewed from the right, rotates in a counter-clockwise direction and conveys more coal along the side of the conduit 2S near the chambers 29. The screw conveyor 23 exerts the greatest pressure against the fuel near the bottom of the conduit 26 and the bottom of the chambers 29, since at successivelyhigher elevation there is a greater tendency for the coal to ride over the hub of the horizontal screw 28 away from the vertical screws 3l Thus, with the vertical screws 3l in their lowest position, as shown in Fig. 4, the coal will be compacted between the lowest full turn of the flights thereof, and as the vertical screws are raised from the zone of greatest pressure against the fuel, the

taining the gear 66 and the vertical screw section 3| in driving engagement. For the purpose of raising and lowering the screw section 3|, a threaded tap bolt 95 is provided which is threaded through a bracket 99 fixed to the furnace wall. One end of the tap bolt 95 is secured to the lower end of the square shaft extension 94 while the other end carries a knob 91 for turning the tap bolt 95. Thus by threading the bolt 95 in or out of the bracket 95, the square shaft 94 and hence the screw 3| may be raised or lowered.

In Figs. 6, 7, 8 and 9 is shown a modification of the fuel distributing mechanism of the stoker installation. As in the preferred form of the invention, a conduit |99 extends transversely along the upright walls |9| of a plurality of furnaces |02 at the bottom of the firing openings |93, and a screw conveyor |94 advances fuel therethrough. Also as in the preferred form, discharge conduits preferably formed integral with the conduit |99 are arranged to receive fuel from the conduit |09 and screw conveyors |96 elevate the fuel to the firing openings |93. From the open upper end of the discharge conduits |95, the fuel is forced through a short elbow |91, which is formed with the iredoor |08, and is discharged therefrom in the firing opening.

A nozzle block |99 is mounted adjacent the ybottom of the firing opening |93 between the discharge conduit |95 and the furnace wall |9|. The nozzle block |99 is provided with a ledge i on which is seated a trough ||2 arranged to receive fuel from the elbow |91. The trough ||2 has a depending annular boss ||3 tting within an annular recess ||4 in the ledge whereby the trough ||2 may swing in an arc about a vertical axis. Means, to be described later, are provided for continuously oscillating the trough ||2.

The trough |2 is preferably horse-shoe shaped in horizontal cross section, and includes in addition to the bottom wall ||5, the upstanding curved outer wall H9. Fuel is projected from the trough ||2 in aerial paths over the firebed by fluid under pressure issuing through the jet openings ||1, from the chamber ||8, which is formed in the upstanding trough wall I6. Fluid under pressure passes from a suitable source of supply through the supply pipe |9 to the nozzle block |09 and thence to the chamber ||8 by the passages |29, |2| and |22 `formed in the nozzle block |09, ledge the boss ||3 and trough bottom wall |5, respectively.

The fuel conveying screw |04 and the ash conveying screw |24 are operated from the same source of power as in the preferred form of the invention, and the shaft |25, as in the preferred form is operated from the ash conveying screw. In the modified form of the invention, the means for oscillating the trough ||2 is operated from the shaft |25, thus coordinating 'the rapidity of oscillation of the trough I2 with the speed of the fuel conveying screw.

Fixed to the ash trough |26 is a bearing |21 in which is mounted a short longitudinally extending shaft |28. The shaft |28 carries at one end a bevel gear |29 meshing with a bevel gear |39 mounted on the shaft |25 whereby the rotary motion is transmitted to the short shaft |28. At its other end, the short shaft |28 carries a disk |49, through which near its periphery is threaded a tap bolt |3| extending beyond the outer face of the disk. The projecting portion of the tap bolt engages a slot |32 in a lever |33, pivotally mounted at its lower end, as at |34. Thus, as the shaft |28 and disk |49 rotate, engagement of the tap bolt in the slot |32, will cause the lever |33 to rock back and forth about its pivot |34. At its upper end, the lever |33 is flexibly connected to a transversely extending rod |35 by a link |36. rIhe rod |35 is mounted in grooves |31 formed in the nozzle block |99 and is free to reciprocate as the free end of the lever travels back and forth. The rod |35 is provided with the racks |38 which engage with teeth |39 on the outer surface of the curved upstanding trough walls H5 whereby the troughs |l2 are oscillated as reciprocation of the rod |35 occurs.

I claim:

l. A stoker for a plurality of furnaces arranged side by side, each of said furnaces having a furnace front provided with a firing opening, said stoker comprising a fuel feed conduit spaced from and extending along said furnace fronts substantially at the level of the lower margin of said firing openings, a screw conveyor in said conduit for advancing fuel therethrough, a piurality of feed devices, each of said devices cornmunicating at one end with said conduit for receiving fuel therefrom and communicating at their respective other ends with a respective ring opening, said feed devices each including an upright conveyor screw for elevating fuel to a respective firing opening, means for raising and lowering said upright conveyor screws for varying the amount of fuel delivered to said ring openings by said upright conveyor screws, and means at said openings for projecting fuel into said furnaces in aerial paths.

2. A stoker for a plurality of furnaces arranged side by side, each of said furnaces having a furnace front provided with a firing opening, said stoker comprising a fuel feed conduit spaced from and extending along said furnace fronts substantially at the level of the lower margin of said firing openings, a screw conveyor in said conduit for advancing fuel therethrough, a plurality of feed devices, each of said devices communicating at one end with said conduit for receiving fuel therefrom and communicating at their respective other ends with a respective firing opening, said feed devices each including an upright conveyor screw for elevating fuel to a respective firing opening, means for raising and lowering each of said upright conveyor screws independently of the others for varying the amount of fuel delivered to each of said firing openings by said upright conveyor screws, and means at said openings for projecting fuel into said furnaces in aerial paths.

3. In a plurality of furnaces arranged side by side, each of said furnaces having a furnace front provided with a firing opening for conjoint manual and mechanical firing, the combination of a fuel feed conduit spaced from and extending along said furnace fronts substantially at the level of the lower margin of said firing openings, a discharge conduit communicating with each of said firing openings and arranged to receive fuel from said fuel feed conduit, said discharge conduits having an open upper end and terminating at said upper end adjacent the bottom of a respective firing opening, a door for each of said firing openings, said doors each having an outwardly bulged portion surmounting the open upper end of a respective discharge conduit, means in each of said conduits for conveying fuel therethrough and means at said firing opening for projecting fuel into said furnaces in aerial paths.

4.' In a plurality of furnaces arranged side by side, each of said furnaces having a furnace front `provided with a firing opening for conjoint manual and. mechanical firing, the combination of Ya fuel feed conduit spaced from and extending along said furnace fronts substantially at they l said fuel feed conduit for conveying fuel therethrough, an upright screw conveyor in each of said discharge conduits for elevating fuel therethrough and forcing it through the bulged portion of the door into the firing opening, and means at said firing opening for projecting fuel into said furnaces in aerial paths.

5. In a plurality of furnaces arranged side by side, each of said furnaces having a furnace front provided with a firing opening for conjoint man- Vual and mechanical firing, the combination of Ya fuel feed conduit spaced from and extending horizontally along furnace fronts substantially at the level of the lower margin of sai-d firing openings, a plurality of discharge conduits, each of said conduits communicating with a respective firing opening and arranged to receive fuel from said fuel feed conduit, said discharge conduits having an open upper end and terminating at vsaid upper end adjacent the bottom of a respective firing opening, a door for each of said liring openings, said doors having an outwardly bulged portion surmounting the open upper end of a respective discharge conduit, a screw conveyor in said fuel feed conduit for conveying fuel therethrough, an upright screw conveyor in each of said discharge conduits for elevating fuel therethrough and forcing it through the bulged portion of the door into the firing opening, and means at said firing opening for projecting fuel into said furnaces in aerial paths.

fi. A Stoker for feeding fuel to a plurality of laterally spaced furnace firing openings comprisving a fuel conduit having a fuel discharge opening below the level of each of said firing openings, said conduit having a fuel receiving opening at one end thereof communicating with a source of fuel supply, means in said conduit for conveying fuel therethrough from said receiving end to each of said discharge openings, a plurality of fuel feed devices, each of said fuel feed devices providing communication between a discharge opening of said fuel conduit and a firing opening, said feed devices each including an upright conveyor screw for elevating fuel to a respective firing opening, and means for raising or lowering said upright conveyor screws for varying the amount of fuel delivered to said firing openings by said upright conveyor screws.

'7. A stoker for feeding fuel to a plurality of laterally spaced furnace ring openings comprising a fuel feed conduit having a fuel discharge opening subjacent each of said firing openings and a fuel receiving opening at one end thereof, a riser conduit communicating at its upper end with the fuel receiving opening of said fuel feed conduit, a plurality of feed devices, each of said feed devices providing communication between a discharge opening of said fuel feed conduit and a firing opening, a screw conveyor in said fuel feed conduit and a screw conveyor in said riser conduit, means operatively connected to the lower end of said riser conduit screw conveyor for actuating the same, said screw conveyors being provided with shaft extensions projecting through the adjacent ends of their respective conduits, means associated with said shaft extensions for operating the fuel feed conduit screw from the riser conduit screw, an upstanding screw conveyor in each of said fuel devices for elevating fuel to a respective firing opening, a shaft extending aiong the lower ends of said feed devices to a point adjacent said screw shaft extensions, means operatively connecting the adjacent ends of said shaft and one of said screw shaft extensions, said upstanding screw conveyors each having a shaft extension projecting through the bottom of said feed devices and means operatively connecting each of said last named screw shaft extensions with said shaft.

NATHAN M. LOWER. 

